全文获取类型
收费全文 | 3148篇 |
免费 | 271篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 147篇 |
妇产科学 | 63篇 |
基础医学 | 426篇 |
口腔科学 | 130篇 |
临床医学 | 403篇 |
内科学 | 746篇 |
皮肤病学 | 38篇 |
神经病学 | 161篇 |
特种医学 | 347篇 |
外科学 | 386篇 |
综合类 | 34篇 |
预防医学 | 200篇 |
眼科学 | 22篇 |
药学 | 141篇 |
中国医学 | 6篇 |
肿瘤学 | 168篇 |
出版年
2021年 | 32篇 |
2020年 | 34篇 |
2019年 | 45篇 |
2018年 | 54篇 |
2017年 | 41篇 |
2016年 | 43篇 |
2015年 | 56篇 |
2014年 | 72篇 |
2013年 | 95篇 |
2012年 | 100篇 |
2011年 | 124篇 |
2010年 | 101篇 |
2009年 | 115篇 |
2008年 | 133篇 |
2007年 | 129篇 |
2006年 | 91篇 |
2005年 | 90篇 |
2004年 | 92篇 |
2003年 | 93篇 |
2002年 | 108篇 |
2001年 | 99篇 |
2000年 | 95篇 |
1999年 | 72篇 |
1998年 | 74篇 |
1997年 | 72篇 |
1996年 | 79篇 |
1995年 | 66篇 |
1994年 | 57篇 |
1993年 | 57篇 |
1992年 | 62篇 |
1991年 | 44篇 |
1990年 | 61篇 |
1989年 | 70篇 |
1988年 | 73篇 |
1987年 | 76篇 |
1986年 | 64篇 |
1985年 | 68篇 |
1984年 | 40篇 |
1983年 | 30篇 |
1982年 | 36篇 |
1981年 | 30篇 |
1979年 | 32篇 |
1978年 | 27篇 |
1977年 | 31篇 |
1976年 | 26篇 |
1975年 | 43篇 |
1974年 | 30篇 |
1973年 | 35篇 |
1972年 | 28篇 |
1971年 | 24篇 |
排序方式: 共有3433条查询结果,搜索用时 15 毫秒
21.
Does altered biomechanics cause marrow edema? 总被引:21,自引:0,他引:21
22.
23.
24.
Carol Smillie B.N. B.Ed. M.S.C. Katherine Coffin B.A. ME.D. Kathryn Porter B.A. Brenda Ryan B.A. M.B.A. 《Journal of community health》1988,13(3):156-170
The International Conference on Primary Health Care, meeting in Alma-Ata, in the Soviet Union, September 12, 1978, expressed the need for urgent action by all governments, all health and development workers and the world community, to protect and promote the health of all people of the world. The world was caught by the phrase which emerged from this conference, Health For All by the Year 2000 and many have examined the articles of the Alma-Ata declaration and tried to implement them in their corner of the world. This paper describes a community-based smoking-cessation program which was implemented in the province of Nova Scotia, Canada, during the years 1980–1984. Primary to this project was the belief that people have the right and the duty to participate individually and collectively in planning and implementing their health care. This paper describes one community's effort in putting this belief into practice.Carol Smillie, B.N. BE.d. M.S.c. is an Assistant Professor at the School of Nursing, Dalhousie University, Halifax, Nova Scotia, Canada B3H 3J5, Katherine Coffin, BA, MEd is the Program Officer, Nova Scotia Office, Health Promotion Directorate Health and Welfare Canada, 5251 Duke Street, Halifax, Nova Scotia. Canada B3J 1P3. Kathryn Porter, B.A. (Gen)., is the Information and Education Coordinator, Nova Scotia Division Canadian Cancer Society. Brenda Ryan, B.A., M.B.A. is Program Evaluation Analysist, Nova Scotia Department of Health, 6088 Hollis Street, Halifax. Nova Scotia, Canada. This Project was funded by Health and Welfare Canada, Nova Scotia Department of Health, Nova Scotia Division Canadian Cancer Society, Requests for reprints should be addressed to: Professor Carol Smillie. 相似文献
25.
26.
Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability 总被引:1,自引:15,他引:1
La Spada AR; Peterson KR; Meadows SA; McClain ME; Jeng G; Chmelar RS; Haugen HA; Chen K; Singer MJ; Moore D; Trask BJ; Fischbeck KH; Clegg CH; McKnight GS 《Human molecular genetics》1998,7(6):959-967
X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG
repeat expansion in the first exon of the androgen receptor (AR) gene.
Disease-associated alleles (37-66 CAGs) change in length when transmitted
from parents to offspring, with a significantly greater tendency to shift
size when inherited paternally. As transgenic mice carrying human AR cDNAs
with 45 and 66 CAG repeats do not display repeat instability, we attempted
to model trinucleotide repeat instability by generating transgenic mice
with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions
in their genomic context. Studies of independent lines of AR YAC transgenic
mice with CAG 45 alleles reveal intergenerational instability at an overall
rate of approximately 10%. We also find that the 45 CAG repeat tracts are
significantly more unstable with maternal transmission and as the
transmitting mother ages. Of all the CAG/CTG repeat transgenic mice
produced to date the AR YAC CAG 45 mice are unstable with the smallest
trinucleotide repeat mutations, suggesting that the length threshold for
repeat instability in the mouse may be lowered by including the appropriate
flanking human DNA sequences. By sequence-tagged site content analysis and
long range mapping we determined that one unstable transgenic line has
integrated an approximately 70 kb segment of the AR locus due to
fragmentation of the AR YAC. Identification of the cis - acting elements
that permit CAG tract instability and the trans -acting factors that
modulate repeat instability in the AR YAC CAG 45 mice may provide insights
into the molecular basis of trinucleotide repeat instability in humans.
相似文献
27.
28.
Comparative analysis of the mucosal adjuvanticity of the type II heat-labile enterotoxins LT-IIa and LT-IIb 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Cholera toxin (CT) and the heat-labile enterotoxin of Escherichia coli (LT-I) are members of the serogroup I heat-labile enterotoxins (HLT) and can serve as systemic and mucosal adjuvants. However, information is lacking with respect to the structurally related but antigenically distinct serogroup II HLT, LT-IIa and LT-IIb, which have different binding specificities for ganglioside receptors. The purpose of this study was to assess the effectiveness of LT-IIa and LT-IIb as mucosal adjuvants in comparison to the prototypical type I HLT, CT. BALB/c mice were immunized by the intranasal (i.n.) route with the surface protein adhesin AgI/II of Streptococcus mutans alone or supplemented with an adjuvant amount of CT, LT-IIa, or LT-IIb. Antigen-specific antibody responses in saliva, vaginal wash, and plasma were assayed by enzyme-linked immunosorbent assay. Mice given AgI/II with LT-IIa or LT-IIb by the i.n. route had significantly higher mucosal and systemic antibody responses than mice immunized with AgI/II alone. Anti-AgI/II immunoglobulin A (IgA) antibody activity in saliva and vaginal secretions of mice given AgI/II with LT-IIa or LT-IIb was statistically similar in magnitude to that seen in mice given AgI/II and CT. LT-IIb significantly enhanced the number of AgI/II-specific antibody-secreting cells in the draining superficial cervical lymph nodes compared to LT-IIa and CT. LT-IIb and CT induced significantly higher plasma anti-AgI/II IgG titers compared to LT-IIa. When LT-IIb was used as adjuvant, the proportion of plasma IgG2a relative to IgG1 anti-AgI/II antibody was elevated in contrast to the predominance of IgG1 antibodies promoted by AgI/II alone or when CT or LT-IIa was used. In vitro stimulation of AgI/II-specific cells from the superficial lymph nodes and spleen revealed that LT-IIa and LT-IIb induced secretion of interleukin-4 and significantly higher levels of gamma interferon compared to CT. These results demonstrate that the type II HLT LT-IIa and LT-IIb exhibit potent and distinct adjuvant properties for stimulating immune responses to a noncoupled protein immunogen after mucosal immunization. 相似文献
29.
30.
Pre-test local microinjection of arginine-vasopressin (AVP) into dorsal or ventral hippocampus resulted in an improvement of retention performance in an appetitively motivated task. Nevertheless, a better improvement appeared when AVP treatment was performed into ventral hippocampus suggesting a higher sensitivity of this part of hippocampus to the action of AVP. To examine a non-specific behavioral action of the peptide, the effect of AVP treatment on locomotor activity was assessed. When the treatment was given into ventral hippocampus, a reduction of locomotor activity was recorded, whereas after AVP injection into dorsal hippocampus, the peptide failed to alter locomotor activity. 相似文献